Universal machine

the theoretical basis for all computers
East Anglia, 1930

Alan Turing. Science Museum/ Science & Society Picture Library

The theoretical basis for all modern computers was laid down when Alan Turing (1912-54) imagined a ‘universal machine’ in his 1936 paper ‘On computable numbers’. He described a device that would read symbols on a tape and proposed that the tape could be used to program the machine. However it was not until later that Turing’s ideas were realised as practical machines.

Turing studied mathematics at King’s College, University of Cambridge. With the outbreak of the Second World War, he became head of a code-breaking unit at Bletchley Park, home to the Government Code and Cypher School. He used his profound mathematical skill to design, with colleague Gordon Welchman, a series of huge electromechanical code-breaking machines known as ‘bombes’.

Following the war Turing moved to the National Physical Laboratory in Teddington. There he revisited the ideas proposed in 1936 and devised one of the first practical designs for a stored-program computer, called the Automatic Computing Engine or ACE.

Is the Universal machine the most important British innovation of the 20th Century?

Stephen Fry is voting for Universal machine

Right, Stephen Fry here. I’m nominating Alan Turing’s Universal Engine, the Universal Turing Machine. Now, Turing was a genius who helped us shorten the war though his extraordinary solutions to the Enigma code machine that the Germans used and this used his earlier mathematics, which had answered David Hilbert, who was a mathematician famous for posing questions to the world of mathematics. Things like the Poincaré conjecture, and the Riemann hypothesis, and zeta functions, and all these rather glamorous sounding things which I course can’t explain because I of course don’t understand. But, I do get the general sense of the meaning of it all, which is that he had an idea of a machine in order to solve an intellectual problem and then had that rare ability amongst mathematicians to push it through to building machines, which he did in the code breaking, and then he moved on later, in Manchester to the idea of this Universal Machine, which is the first programmable computer, essentially, which instead of being dedicated to a particular task like cryptanalysis, you could use it for programmes and that’s what this world now has. We owe him a huge debt, especially as he committed suicide after being chemically castrated after being taken to court for an act of gay love. So, we owe him everything.